Universal radial grinding machine



1929. P. T. LENNON UNIVERSAL RADIAL GRINDING MACHINE Filed Aug. 24, 1927 3 Sheebs-Shet INVENTO W Nov. 5, 1929. P. "r. LENNON 1,734,735

' UNIVERSAL RADIAL GRINDING MACHINE 1 Filed Aug. 24. 1927 3 Sheets-Sheet 2 I W? n W I \ZI'NVENITORI TTORNEYS Nov. 5,1929. P. T. LENNON 1,734,735

UNIVERSAL RADIAL GRINDING MACHINE Filed Aug. 24, 1927 s Sheets-Sheet 5 TORNEYS Patented Nov. 5, 1929 PATRICK T. LENNON, or CLEVELAND, OHIO, ASSIGNOR TO THE KELLY REAMEB- COMPANY, or CLEVELAND, onro, A oonronArroN or OHIO UNIVERSAL .BADIAL GRINDING MACHINE Application filed Augusta; 1927. Serial No. 214,999.

This invention relates to apparatus for use in grinding cutters. It is more especially concerned with apparatus for grinding radial relief or clearance on the teeth or blades 5 of cutters, such as reamers and the like.

'By this invention radial relief of the desired amount may be provided on cutters of different diameters where the teeth are either straight or spiral and where the teeth are either equally or unequally spaced apart on the cutter. 7 1 e Other advantages and objects of my 1nvention will appear and be pointed out hereinafter.

In the drawings accompanying and forming a part of this specification in wh ch is shown one form of apparatus embodying my invention 1 Figure 1 is a side elevation of an attach- 29 ment for a grinding machine or the like which embodies my invention, a Figure 2 is a top plan View of'the devlce of Figure 1,

Figure 3 is a vertical sectional View taken 7 7 on 11 IIIIII of g- Figure 4 is a view of the pawl, ratchet and cam assembly.

The embodiment of my invention lllustrated herein is an attachment which can be mounted on the bed of a grinding machine or any similar machine having a longitudinal r feed. Thisattachment consists of the fol lowing parts: A carriage 1 is adapted to seat on and slide onthe bed of a grmding machine or the like and to engage with the longitudinal feed of the bed (not shown) for movement past the face of a radial grinder hereinafter shown as a grinding wheel 2.-

This carriage '1 is provided on its front side with two spaced mountings 3 formed with slide-receiving grooves 4 and inclined top surfaces 5 for a purposewhich will presently appear. This carriage 1 is cut away on its' back edge to receive a pivoted platen 6 which ;is carried on pivots 7 mounted on carriage 1 by bearing caps 8.. The carriage 1 is provided at one end with a'bracket 9having an enlarged bored end 10 in which is rotatably mounted a cylindrical driver 11 carryingat one enda drive pulley 12 and formed atits other end with a plurality of driving pins 13 which engage in suitably formed holes 14 in a gear 15.

The platen 6 carries near either end thereof brackets 16 and 17 Bracket 17 carries a work supporting member 18 which, in the present embodiment, is shown as an ordinary 'footstock' with a center 19 to seat in the work.

Bracket 16 is centrally bored and fitted with one end and atthe other end carrying keyed thereto the driving gear 15. Bracket16 also carries adjacent-tothe driving gear 15 a yoke 22 which is split on one side so as to be clamped in adjusted-position by the screw 23. This yoke'22 has a projecting arm 24 which is bored to provide a bearing to receive a rotatable shaft 25 which has keyed thereto at one end a gear 26 meshing with the drive gear 15 and at the other end a gear 27 which meshes with a gear 28. v

The cutter 29, which as is here shown is a reamer with teeth parallel its axis; is supported at one end by the footstock 19 and at the other or shank end by any suitable "chucking device (not shown) carried in the rotating member 20 or by means of a lathe dog secured to the member 20 and about the shank of the cutter 29 in customary fashiom The bracket 16 is also provided with two projecting arms 31 and 32. In arm 31 a shaft. 33 is ro-tatably mounted and carries at one end gear 28 and is formed at its other end with a crank arm and a pin 34 which carries a link 35.

The mountings 3 support on their top'surfaces brackets 36 and 37 which brackets comprise flat portions 36 and 37 to rest on the mountings 3 and are secured thereto.byT- bolts 38 slidably adjustable in grooves 4, and also bored arms 36 and 36 and-37 and 37 The'arms 36 and 37 rotatably support a shaft 39' which has keyedthereto at either end cams 40 having a-plurality of rises and depressions spaced alternately around a the periphery thereof. A ratchet wheel 41' is keyed to one cam 40 adj acentto the link 35,

the link carrying; a pawl 43 on a pin 42. The pin 42'is fixed adjustably in a slot 35 in thelinlr 35 to provide for the step by step rotation of the ratchet wheel 41, and incidentally of the shaft 39, by the pawl -l-3 when the crank 34 is rotating, the adjustment being for the accommodation of cutters of different diameters. e

The arms 36 musi of the brackets 36 and 37 have pins 44 keyed therein. These pins 44 rotatably carry upright guides 45 in each of which pins 46 can be adjustably secured at different positions, each pin carrying a flanged bearing member 47 having a screw threaded nut 48 thereon to clamp a slotted link 49 against the flange of themember 47 in any desired position. Each upright 45 car ries a roller 50 to engage with the cams 40.

- S rin s 45 are secured in tension to uori hts p a: l a

45 and to carriage 1 to press rollers 50 against cains 40 at all times and, when the rollers 50 engage with the falls of cam 40, to pull guide .45 toward cam40 thereby tilting platen 6 toward grinder 2. The rollers 50 follow the rises and falls of thecams 4O forcing the rollers 50 outwardlywith respect to the shaft 39 with a pivoting or swinging motion of the arm 45 about the pin 44 which motion is transmitted through the links 49 to the swinging or pivoting platen 6 with the result that the Work blank or cutter carried thereby is moved away from the grinder 2. WVhen the rollers 50 are pressed against the low spots as by springs 45 between the rises on cams 40 the same action takes place except that the cutter 29 is moved towards the grinder 2. The rotatable shaft 39 has a detent carri'er 51 keyed thereto. This carrier has a plurality of radially extending matches or slots '52, in each of which .a finger 53 is pivoted at one end and provided with a cam follower roller 54 at the other end. These followers 54 follow a cam 54 which seats on the detent .which encircles the carrier 51 and seats in slots in fingers '53. Each finger 53 is provided with a detent 59 'adjustably secured thereto; When the cam follower 54 of any given finger 53 rides up over the rise on the cam 54 the detent 59' carried by such finger 53 is moved towards the cutter 29 sufiiciently farto engage withatooth thereofand remain in such engagement until'the tooth has rotated thedete'n't carrier 51 and its follower 54 far enouglrfor the follower to pass off the cam surface which has the same radius of curvatureas the cutter teeth and for detent '59 to disengage from the tooth. This posi T 'L-ion corresnonds with cam 54 theend of'the rise on The foregoing device operatesjs'ubstaa itially' asfollows; The grinder 2 is rotated,

and carriage 1 is set in motion longitudinally of its supporting bed; The pulley 12 is rocams 40, shaft 39 and detent carrier 51. R0-

tation of the detent carrier 51 moves one of the rollers 54 up onto the rise on cam 54 bringing its detent 59 into a position to engage beneath a tooth on the cutter 29. Such motionbrings the fallsor hollows on cams 4O opposite the rollers 50 and permits springs 45 to pull the rollers 40 toward shaft 39 and, through links 49, tilt. swing or pivot the platen 6 and move the cutter toward the grinder 2 so that the latter may remove from the tooth opposite the one engaged by detent 59 a snliieient amount of material to provide the desired radial relief on such tooth. Continned rotation of the detent carrier 51 and cutter 29 results in tilting of platen 6 and cutter 29 away from grinder 2 since links 49 positively pull these parts away from the grinder when'rollers 50 engage the riseson earns 40. This movement is accompanied by disengagement of detent 59 from the cutter tooth and is followed by engagement of pawl 43 with the next ratchet and of theanext detent 59 with the next tooth on the cutter.

It will be understood thatvthe ratehets merely rotate the detent-carrier sufficiently to move the succeeding detent into the path mitting this motion. Obviously-it will be advantageous to insert between the rotating hollow shaft whlch supports the cutter being ground and the shaft carrying the cams and detents, gears of such a ratiothatthe ratchet will act to turn the detents through a distance somewhat less than'the distance between successive cletents 'while the Work is being rotated at a distance between successive cuttin edges; Thus the 'feedsby the ratchet an by the blades of the Workalternate; the

ratchet rotating the detent to bring a detent into position to be engagedlby the cutter,- While the blades of the cutter are not in position to engage detents, and, upon the cutter blade and per-v engaging a detent, this takes up therot'ati'on of the detent carrying shaft and produces the actual feed against' the grinding wheel. Obviously the motioncofthe detent when-enby the cutterblade is much more 'rapid than when it is beingmoved by the ratchet, i

as during the former period it move's atslibstantiahy the same angular velocity (Sf-the cutter blade while during the latter period its motion is inversely proportional as the number of d'etents to the-numberofcutter blades; 7 v- 7 It will be understood that since the detents 59 are slightly ahead of the teeth on the cutter 29 this apparatus will function as intended regardless of the spacing between the teeth on the cutter which spacing is usually varied between the teeth. For example, if the teeth are unequally spaced the dwell of the rollers 54: on the rise of cam 54 will accommodate such unequally spaced teeth and will insure tilting of the cutter 29 toward grinder 2 at the proper time. The cutter is continuously rotated and is fed longitudinally past grinder 2 so that radial relief is ground on all teeth or blades of the cutter for their full length.

My device is adaptable to cutters having either straight or spiral teeth. -With the latter, the detents 59 are adjusted so that they are substantially parallel to the edgesof the teeth of the cutter. When employing my invention with cutters having spiral teeth, and at other times if desired, it may be advantageous to provide means for preventing movement of the detent carrier 51 longitudinally of the shaft 39. To this end I have shown a clutch 61 which may be secured to the carrier 51 and in which may seat an arm 62 adjustably secured to a bracket 63 or the like attached to any suitable member, for example, to the member 1 or to any member moving therewith.

The mountings 3 and 4 have their top surfaces inclined at an angle to the aXis of the cutter 29 which angle insures engagement of the detents 59 with the teeth at the same angle for cutters of different diameters. By suitably adjusting the brackets 36 and 37 on the mounting 3, cutters of different diameters may thus be accommodated.

It will be understood that although the cutter teeth or blades are spaced apart from each other by varying amounts, the teeth or blades are always arranged in diametrically opposed pairs so that there is always a tooth diametrically opposite to the one engaged by a detent 59 and adjacent to grinder 2. The tilting of the cutter toward grinder 2 is so timed by detents 59 and cams 40 that grinder 2 removes a progressively increasing amount of stock from a given tooth there by giving it the desired radial relief.

It will also be understood that the rises and falls of cams 40 are greatly exaggerated in the foregoing figures for the particular cutter shown, but that the rises and falls can be made of any desired size.

Having thus described my invention so that others skilled in the art maybe enabled to practice the same what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

1. An attachment for a grinding machine comprising a longitudinally movable carriage, a rotatable shaft mounted thereon, 2.

- pivoted platen carried by said carriage and adapted to rotatably support a cutter having teeth or blades to be ground, means for rotating-the said shaft and said cutter, and

means operatively associated with said shaft .and platen for tilting the latter and moving to the tooth in engagement with the grinding wheel.

2. Apparatus for grinding radial relief on I the blades or teeth of a cutter comprising in comb1nation,.1ncans' for rotating a cutter,..a

shaft carrying detents arranged circularly about the shaft and successively engageable with successive teeth or blades on the cutter, means for periodically rotating the shaft, and means actuated by engagement of a detent with a cutter blade or tooth and including a cam for moving the cutter into and out of engagement with a grinding wheel.

s 3. Grinding apparatus for use in grinding radial relief on cutter blades which comprises a rotating grinder support for the cut ter being ground, a feed translating the cutter longitudinally relative the grinder, a plurality of circularly arrangedblade-engaging fingers rotatably mounted to engage successive blades of the cutter, and feed means for moving the cutter transversely toward the grinder operated by said fingers.

4:. Apparatus for grinding radial relief on cutter blades which comprises a rotating grinding wheel, a pivoted support for the cutter, means for rotating the cutter in said support, a plurality of blade-engaging fingers rotatably supported and adapted to be successively engaged by successive blades of the cutter during rotation thereof, means for radially moving the fingers toward the cutter at predetermined intervals, said means comprising a non-rotatable cam and followers carried by the fingers bearing thereon, and a feed transverse said cutter for moving the same toward the grinding wheel and actuated by said fingers. x f

5. Apparatus for grinding radial relief on cutter blades which comprises a rotating grinding wheel, a pivoted support for the cutter, means for rotating the cutter in said support, a plurality of blade-engaging fingers rotatably supported and adapted to be successively engaged by successive blades of the cutter during rotation thereof, means for radially moving the fingers toward the cutter at predetermined intervals, said means comprising a nonrrotatable cam and followers carried by the fingers bearing thereon,

means for retaining the followers in engagement with the cam, and a feed transverse said cutter for moving the same toward'the grind- 111g wheel and actuated by said fingers.

6. Grinding apparatus for grinding ra-- dial relief upon cutter blades, comprising a rotating grinding Wheel, a support for the cutter movable toward and from said grind ing Wheel means for rotating the cutter, a feed for moving the cutter toward and from the wheel and provided with actuators adapted to be engaged by the blades of the cutter, the feed apparatus being slidably adjustable upon an inclined support so that adjustment of the feed for different diameters of cutters may be effected While maintaining the angle of presentation of the cutter teeth to the grinder.

In testimony whereof I hereunto afiix my signature. this 16th day of August, 1927.

' PATRICK T. LENNON. 

